Respiratory mucosal immunity against SARS-CoV-2 after vaccination and infection

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Presentation Time: 03:15 PM - 04:30 PM
Poster Board Number: B920
Abstract ID: 5071

Presenting Author:
Jinyi Tang , Research Associate at Univ. of Virginia Sch. of Med.

Abstract:

 

The current COVID-19 mRNA vaccine is effective in systemic immune memory but lacks in generating mucosal anti-SARS-CoV-2 immunity. While prior SARS-CoV-2 infection establishes respiratory immunity, its strain-specific nature and limited duration pose challenges for sustained protection. Recent research has shown that hybrid immunity, a combination of vaccination and infection, results in a more robust, durable, and broadly reactive immune response in circulation compared to vaccination or infection alone. However, the characteristics and protective mechanisms of hybrid immunity in the respiratory mucosa are not fully understood. Moreover, it remains to be determined whether mucosal booster vaccines could potentially induce responses that are even stronger and more broadly reactive than hybrid immunity. Here, we collect nasal wash, bronchoalveolar lavage, and blood from controls, vaccinee, convalescents, or hybrid individuals. We found that hybrid individuals displayed higher levels of specific Ab, nAb, and B cells than other groups in the respiratory mucosa. In our mouse models, although hybrid immunity showed significant mucosal humoral and cellular immune responses, an adenovirus-based mucosal vaccine booster induced more robust protective respiratory immunity against SARS-CoV-2 variants. Our findings reveal the mechanisms of protection of hybrid immunity and underscore the importance of developing mucosal vaccine boosters that can emulate heightened mucosal immunity.